The wording depends on the rule set but generally:
OBR:
6.01 Interference, Obstruction, and Catcher Collisions
(a) Batter or Runner Interference It is interference by a batter or a runner when:
(3) Before two are out and a runner on third base, the batter hinders a fielder in making a play at home base; the runner is out;
I don't have NFHS in front of me, but I'm pretty sure the batter both can't make a movement that hinders the play AND has to vacate the area if a play is being made if possible.
Obviously in both cases a batter (or runner depending on situation) is not out just because he didn't move out of the box. If he is in the box, but doesn't hinder the play - he is fine.